The Jones Falls turned a bright, neon green Friday afternoon amid what officials said was a test using dye to trace a leaky pipe.
Baltimore public works spokesman Kurt Kocher said a city worker was using the dye to trace what was thought to be a possible water main break and used "maybe a little too much" dye.
The dyed water caused concern for some. Curt Kotula, creative director at marketing agency Fastspot, shared a video on Twitter of bright green water appearing to bubble out from the western bank of the Jones Falls near Mill No. 1, where the company is based.
He said he and a group of colleagues noticed it from their office window.
“Something to worry about or not?” he wrote.
Later Friday afternoon, the green color appeared diluted and less bright.
Kocher said dyes are employed to find the source of sewage leaks.
Leaks of about 189 million gallons of sewage and sewage-tainted water have been reported in the city so far this year, according to state environmental records.